Lushly planted green roofs that change color with the season are the centerpieces of two new buildings in downtown Seattle. The roofs provide not only a distinctive design feature for the buildings but also important environmental and economic benefits for the city of Seattle.

The Justice Center’s 8,500 square-foot garden roof was completed in 2002. From the very beginning, sustainability was a top design criterion, says Knut Hansen, senior associate for project architect NBBJ Design. The design features an intricate planting design guided by an image of sunlight reflected in a shallow streambed. But not only is the design visually appealing, the plants on the roof retain moisture and reduces the amount of stormwater entering the city’s storm sewer system.